Device for producing high-pressure pulse-type jets of liquid

ABSTRACT

The invention describes a device for producing pulse-type highpressure liquid jets created by the impact of a piston on the liquid contained in a chamber having a hole for the outflow of the liquid. For this purpose the piston is accelerated in the cylinder by compressed gas and, after producing an impact returns to the initial position compressing the gas by feeding the liquid under pressure into said cylinder.

United States Patent 1111 3,593,524

(72) Inventors German Petrovich Chermensky [52] US. Cl fill/54.5115 ulitsa Novskogo, II, In. 3; [51] Int. Cl v. FlSb 7/00 Mikhail Andreevich Nikiforov, ulitsa [50} Field of Search (SO/54.5 HA Kirova, 33, kv. [9; Jury Vladimirovich Gaiduk, ulitsa Shkolnaya, 21, kv. I3; 1 References Cited Klavdia Mikhailovna Khvoschevskaya, UNITED STATES PATENTS Kim", 39; 8 3,412,554 1 1/1968 Voitsekhovsky et al 60/545 HA Natapov, Rynoehny proezd, 3, kv. ll; Alexei Andreevich Kilin, ulitsa Kutuzova, 'WY EMWWPCMRO cfoyle ss, kv. 2; Mikhail Antonovich Shvetsov, 4mm"! Hammer-A M- ZHPClc Y m Ryaunsknya 9 a" of Novokuzne'sk, Attorney-Waters, Rod1t1, Schwartz & N1ssen U.S.S.R.

[21] Appl. No. 887,645 [22] Filed Dec 23 9 9 ABSTRACT: The invention describes a device for producing [45] p d Ju|y 2 1971 pulse-type high-pressure liquid jets created by the impact of a piston on the liquid contained in a chamber having a hole for the outflow of the liquid. For this purpose the piston is ac- [54] DEVICE FOR PRODUCING HIGH-PRESSURE celerated in the cylinder by compressed gas and, after produc- PULSE-TYPE JETS OF LIQUID ing an impact returns to the initial position compressing the 1 Claim, 3 Drawing Figs. gas by feeding the liquid under pressure into said cylinder.

wllllllifillfllll ISZIJIIAMIWI4 JYIAVIIIA-W a?) an? I DEVICE FOR PRODUCING HIGH-PRESSURE PULSE- TYPE JETS OF LIQUID I The present invention relates to the devices for building up extra-high pulse pressures of liquid produced by the impact of a piston on a liquid in a chamber which is provided with a hole for the outflow of the liquid under pressure.-

More specifically, the invention relates to the devices where the piston is returned after the impact to the initial position by the liquid.

The invention may be utilized for breaking up rocks by the direct action of a high-pressure jet of liquid; for the hydraulic pressing in which the liquid forced under pressure from the chamber is fed into a' closed die with a blank inside; and for forging, pressing and cutting of metals 'in which the liquid under pressure actuates the movable piston to which the working tool is secured. 7

Known in the art are devices for producing extra-high pulse pressures of liquid (for example, the British Pat. No. 108 I076 the U.S., Pat. No. 3412554 ,the French Pat. No. 1415034 granted to B. V. Voitzekhovsky, et al.) comprising a cylinder with a piston inside, dividing the cylinder space into two chambers. The first chamber communicates with the compressed gas vessel whereas the second one is filled with liquid and has a hole for the outflow of liquid under pressure produced by the impact of the piston which is accelerated by compressed gas in the first chamber.

From the viewpoint of the method bywhich the piston is returned .to the initial position for compressing the gas in the first chamber the known devices are divided into two-categories.

in the first category the working piston is returned by a cocking mechanism comprising at least one power cylinder whose piston interacts periodically with the working piston of the cylinder with the aid of a cam-type gripping device.

In the devices of the second category the working piston, is returned to the initial position after the impact by feeding the liquid under pressure into the cylinder space from the side of the second chamber if the piston is of a'single-step construc tion or by connecting to drainage the cylinder space located between the piston steps, said space adjoining the secoi'td chamber, if the piston is of a two-step construction. In this case the liquid is drained from the cylinder space during the working stroke of the piston through the holes in the sidewall, covered by slide valve. The operation of this slide valve is crintrolled by another slide valve connected to the pressure line delivering the liquid, the body of the latter valve being secured to the end wall of the cylinder at the side of the first chamber while its movable element protrudes into said chamber and interacts with the piston when it returns to the initial position after the impact.

The utilization of the known device has shown, that the functioning of the controlling slide valve depends upon changes in the pressure of the liquid in the pressure line.

When the liquid pressure in the line is dropped the speed of operation of the slide valves is reduced which leads to a reduction of the number of piston impacts (thus reducing the socalled impact rate" of the device). g

When the pressure in the line rises, the operating speed of said valves increases so that the piston in the cylinder starts to be accelerated before the liquid has been evacuated from the cylinder and, as a result, there is no sharp impact of the piston on the liquid in the second chamber and the piston starts to be cocked after the impact without forcing the entire amount of liquid from the second chamber. Besides, the inertia forces occasioned during the operation of the device likewise interfere with the functioning of the slide valves.

All this, taken together, impairs the efficiency of the device.

The main object of the invention resides in improving the controlling slide valve in such a way as to exclude the effect of the liquid pressure variations in the pressure line on the operation of this valve and of the slide valve covering the drain holes.

According to the invention, the improvement consists in that the sidewall of the cylinder has a channel opening into the second chamber and covered by the piston at the end of its stroke during the impact on the liquid in this chamber, while the controlling slide valve has a plunger, the space between said plunger and the slide valve body being connected to said channel by a line communicating via a flow rcstrictor with the liquid pressure line.

Now the controlling'slide valve comprises an unbalanced movable element" which may occupy only the" meme positions, and a plunger which is moved only by the pulse of pressure which is equal to the pressure of the liquid in the pressure line and acts duringthe period when the channel the second chamber is overlapped by the piston. a

The state of unbalance of the movable elerncntmakes it possible to eliminatethe' effect of the inertia'forces on the operation of the controlling slide valve occasioned during the operation of the'device. 1

The use of the pressure pulse for moving the plunger and,

together with it, the movable element of the controllingslide valve ensures the shifting of the movable element which covers the drain holes of theslide valve immediately after thc' impact of the piston on the'liquid, r

This ensures's'teady operation of the slide valvesirrespective of the variationsof the liquid pressure in the pressure line.

Now theinvention will be described in detail by wayof example with reference to the accompanying drawings'in which:

chamber for striking the liquid therein.

As illustrated 'in FIGS. 1 'ahd3, the claimed device'comprises a cylinder 1 accommodating a 'working piston'2 which divides the cylinder cavity into two chambers 3 and 4. The low-pressure chamber 3 communicates via ports S with a compressed gas vessel 6. The high-pressure chamber 4 communicates via channels 7 and a line 8 which has a flow restrictor 9 with the liquid pressure line'l0 and has a hole 12 in the end wall ll of the cylinder 1 for the outflow of the liquid under pressure'after it has been struck by the piston 2'which performs a translational motion for this purpose by the action of the compressed gas in the chamber 3.

In the given example of realization of the invention the piston 2 is of a two-step construetion'and its large-diameter step 13 is located at the side of the chamber 4 while the smalldiameter stepl 4 is located at the side of the chamber 3. The

space of the cylinder l between the steps 13 and of the piston 2 is divided by a'partition'l5 into two'chamb'ers l6 and 17.

The chamber 16 is in constant communication via ports 18 with the pressure line lfl antlithe liquid entering this chamber from said pressure line cocks thepiston 2 to the initial position after the impact. The chamber 17 is periodically communicated with the pressure li'n'eflo and simultaneously with the chamber 16 or with a drain hole 19 through ports 20 by means ofa slide valve 21. t I

The liquid entering the chamber 17 assists to a certain extent in accelerating the piston 2 towards the chamber 4. Therefore, to make up for the losses of pressure taking place when the liquid is forced out of the chamber 16 into the chamber 17 during the acceleration of the piston 2, the piston step 13, as pointed out above,'has a larger diameter. For the same purpose the outlet hole of the pressure line 10 is located opposite the ports 20 of the chamber 17 since this reduces the hydraulic resistance to the greatest measure.

The slide valve 2! accommodates in its body 22 a movable element 23 in the form of a two-step bushing with an internal circular recess 24 and ports 25, saidbushing moving outside the cylinder 1. The movement of the element 23 is limited by the partition 26 secured .outside the cylinder 1 and coming short of the wall of the body 22; the space of the body 22 is divided by projections 27 into spaces 28 and 29.

The operation of the slide valve 21 is controlled by the slide valve 30 whose body 31 is secured in the end wall 32 of the cylinder 1 at the side of the chamber 3. The movable element 33 of the controlling slide valve 30, accommodated in its body -31, protrudes into the chamber 3 and interacts periodically The body 31 of the controlling slide valve 30 has channels 45 and 46 opening into the drain channel 47, and channels 48, 49 and 50; the channel 48 is connected to the pressure line by a line 51; the channel 49 is connected with the space 28 of the slide valve 21 by a line 52; and, finally, the channel 50 is connected by a line 53 with the channel 54 opening into the chamber 4 and covered by the piston 2 at the end of its stroke during the impact on the liquid in said chamber.

The line 53 is connected to the pressure line 10 via a flow restrictor 55.

Let us consider the functioning of the claimed device from the moment when the piston 2 after the impact is in the chamber 4, covering the channel 54, and the chamber 17 of the cylinder 1 is filled with liquid as shown in FIG. 1.

As the liquid is fed from the pressure line 10 into the chamber 16 of the cylinder 1, the liquid pressure in the line 53 becomes after a certain time equalto the pressure in the line 10; as a result, the element 33 of the controlling slide valve 30 will be acted upon on one side by the plunger 39 moved by the liquid entering the space 44, while on the other side it will be acted upon by the pressure of the liquid in the space 40, con: nected via the hole 37, channel 48 and line 51 with thepressure line 10, on step 34 and compressed gas in the chamber 3. Inasmuch as the liquid pressure in the pressure line 10 is higher than the gas pressure in the vessel 6, the element 33 will be moved towards the chamber 3.

Approximately in the middle of the travel of the element 33 the space 40 will be put in communication with the drain channel 47 via the hole 37 in the step 34, space 41 and chan-' nel 45 in the body 31, while the step 36 of the element 33 will be acted upon by the liquid entering the space 43 through the hole 38, space 42 and channel 48 via the line 51 from the pressure line 10.

After the reversal of the element 33 the liquid is delivered through the space 42 of the slide valve 30, channel 49 and line 52 into the space 28 of the slide valve 21, moving its'element 23 towards the space 29 because the cross-sectional area of the element 23 is larger at the side of the space 28 than it is at the side of the space 29.

At the end of its travel, the element 23 comes to bear against the projection 27, separating the chambers 16 and 17 and connecting the latter of the two with the drain hole 19 via the ports 20, recess 24 and ports 25.

Now, being acted upon by the pressure of the liquid entering the chamber 16, the piston 2 starts to be cocked, opening the channel 54 in the chamber 4. Owing to the provision of the flow restrictor 5'5 the liquid pressure in the line 53 becomes equal to the atmospheric one the plunger 39 is moved in the space 44 by the liquid in the space 43 all the way to bear against the body 31 of the slide valve 30 as shown inFig. 2 while its element 33 is held by the pressure of the same liquid in the former position.

At the end of cocking the piston 2 will press the element 33 and shift it to the position illustrated in Fig. 3. The line 52 will then be connected with the drain channel 47 via the channel 49, space 42 and channel 46 while the element 23 of the slide valve 21 will be moved by the pressure of liquid in the space 29 towards the space 28, covering the drain hole 19 of the .body 22 and interconnecting the chambers 16 and 17 via the space 29 The piston 2 starts to be accelerated by compressed gas In the chamber 3, the liquid is forced from the chamber 16 into the chamber 17 and the piston 2 strikes the liquid (which filled the chamber 4 via the channel 7, line 8 and flowrcstrictor 9 from the line 10 while the piston was being cocked), forced out in the form of a high-pressure jet through the hole 12.

While the piston 2 is being accelerated and forces the liquid from the chamber 4 up to the moment of covering the channel 54, the element 33 of the controlling slide valve 30 is held in the position shown in Fig. 3 because the line 53 is connected with drainage through the opened channel 54, the space 43 is connected with the drain channel 47 through the hole 38 in the step 36 and channel 46, while the space 40 is connected with the'pressure line 10 through the hole 37 in the step 34 via the channel 48 and line 51.

At the end of the stroke of the piston 2 the latter covers the channel 54 after which the operating cycle is repeated over again in the same sequence.

In the claimed device the piston 2 may be single stepped and may be returned to the initial position after the impact by the liquid fed into the space of the cylinder 1 from the side of the chamber 4 as it is described in several patents quoted above. In this case the design of the slide valve will be simplified.

Industrial tests of the claimed device have confirmed steady functioning of the distributing and controlling slide valves.

What we claim is:

1. A device for producing pulse-type high-pressure jets of liquid comprising a compressed gas vessel; a cylinder accommodating a piston,'dividing said cylinder space into two chambers one of which is connected with said compressed gas vessel while the second one is filled with liquid and has a hole for the discharge of liquid under pressure when it is struck by the piston accelerated by compressed gas in the first chamber; a pressure line feeding liquid under pressure into said cylinder cavity for returning the piston to the initial position after the impact; said cylinder has a hole in the sidewall for draining the liquid during the working stroke of the piston; a slide valve for covering the drain holes in the sidewall of the cylinder; a slide valve controlling said slide valve and having a body secured in the end wall of the cylinder at the side of the first chamber, the movable element of the controlling slide valve interacting with. the piston when it is returned to the initial position after the impact; a channel in the sidewall, of said cylinder, opening into the second chamber and covered by the piston at the end of its working stroke during the impact on the liquid; a plunger accommodated in the body of said controlling slide valve; a line connecting the space of the controlling slide valve between its body and the plunger with said channel and connected via a flow restrictor to said liquid pressure line. 

1. A device for producing pulse-type high-pressure jets of liquid comprising a compressed gas vessel; a cylinder accommodating a piston, dividing said cylinder space into two chambers one of which is connected with said compressed gas vessel while the second one is filled with liquid and has a hole for the discharge of liquid under pressure when it is struck by the piston accelerated by compressed gas in the first chamber; a pressure line feeding liquid under pressure into said cylinder cavity for returning the piston to the initial position after the impact; said cylinder has a hole in the sidewall for draining the liquid duRing the working stroke of the piston; a slide valve for covering the drain holes in the sidewall of the cylinder; a slide valve controlling said slide valve and having a body secured in the end wall of the cylinder at the side of the first chamber, the movable element of the controlling slide valve interacting with the piston when it is returned to the initial position after the impact; a channel in the sidewall, of said cylinder, opening into the second chamber and covered by the piston at the end of its working stroke during the impact on the liquid; a plunger accommodated in the body of said controlling slide valve; a line connecting the space of the controlling slide valve between its body and the plunger with said channel and connected via a flow restrictor to said liquid pressure line. 